Omega
speedmaster tritium 806 caliber

Vintage Omega Speedmaster watch, reference ST 145.022, tritium dial, dated 1992. This iconic watch was worn by astronauts of NASA and ESA during Space Shuttle and Skylab missions. A pre-owned and collectible chronograph, it features the Omega Caliber 861 with 17 jewels — the second movement used in the Speedmaster’s storied journey. This movement is now highly sought after among collectors, considered a robust successor to the fragile Caliber 321 that preceded it. Caliber 861 was used by the majority of Space Shuttle astronauts, adding to its legacy. The rare sandy patina developed over time on the dial indices makes this example even more desirable.

The 42 mm screw-down caseback is decorated with the iconic Seahorse medallion and the legendary inscriptions confirming the model’s use during space missions. This mechanical movement, hand-wound and adorned with 17 jewels, operates at 21,600 vibrations per hour and features a warm copper-colored finish. Technically, the Caliber 861 was developed by Omega from the Lemania 1873, with an upgraded flat hairspring and cam-switching system.

Inside the case, the movement is protected by an anti-magnetic cover placed between the movement and the caseback. The Lemania 1873 movement is renowned for its reliability and resilience. It is praised for its ability to endure large temperature fluctuations and withstand long-term vibrations and shocks. This legendary dependability has made it the foundation for numerous flagship models from respected watchmakers — including Universal Genève (Caliber 84), and Breitling with its Navitimer chronograph. Additionally, the Breitling Caliber 12 powering the Navitimer Cosmonaute with its 24-hour display is based on the Lemania 1877 — technically identical to the 1873, but with the hour hand rotation speed halved.

Regarding dial specifics, this Speedmaster features the C5 “Short-S” dial version used between 1991 and 1997. The Moonwatch dial is marked with two dots beneath the 12 o’clock index. The “S” in “Speedmaster” is the shortened version. The inscription “T Swiss Made T” sits at the bottom of the dial, with wide spacing between the Ts. Three subdials for hours, minutes, and continuous seconds offer a clean and legible layout. The chronograph function uses a small seconds counter with Stop-and-Go functionality. For standard time display, a large central seconds hand (Flat Second) is paired with Tritium-coated B5 hands for hours and minutes. A fixed tachymeter bezel, marked counterclockwise from 60 to 500, surrounds a Hesalite crystal.

Omega collector’s watch in stainless steel. Waterproof rating is not guaranteed due to age. Given its 1992 production, this model has become increasingly hard to find in good condition. Its market value is expected to rise significantly, potentially reaching the level of the earlier Caliber 321 Speedmasters. Its exceptional mechanical and cosmetic condition further boosts its appeal for collectors. You can read a detailed article on the history of the Omega Speedmaster by following this link, and another on the history of Omega and its record-breaking watches on our "Watch Stories" blog page.

Discover our pre-owned Omega Speedmaster